A rigger is a person who specialises in lifting and moving large or heavy objects. The equipment available to riggers on construction sites is often limited, so they rely on equations to help them figure out how to safely lift and move objects. The rigging equation for calculating the mass of a hollow steel pipe is given below:

???? = 24????????(???? − ????)

Where ???? is the mass of the pipe in tonnes (t), ???? is the length, ???? is the outside diameter, and ???? is the wall thickness of the pipe, all measured in metres (m).

**a) What is the mass of a 6 m pipe with an outside diameter of 0.3 m and a wall thickness of 5 cm? Give your answer to the nearest tonne. **

**b) Transpose the equation to make ???? the subject.**

**c) A steel pipe needs to be moved into place on a construction site using a crane. The rigger has a sling available that is approved for use on pipes that have an outside diameter less than 1 m. If the steel pipe to be moved is 8 m long, has a wall thickness of 0.04 m, and has a mass of 7.5 t, can the rigger safely move the pipe? Use mathematics to explain how you determined your answer **

#### Top Answer

1.8 ton D >... View the full answer